# Reconstruction of vector field from spherical harmonic coefficients

1. Oct 26, 2008

### ronslow

The JGM3 model of earth's gravity is expressed in the form of coefficients C and S to Legendre polynomials in r, theta and phi which give the gravitational potential

U = $$\sum$$$$\sum$$ CV + SW

Can anyone tell me the algorithm for calculating acceleration vector g(r, theta, phi) from the coefficients, i.e. $$\Delta$$.U expressed as a polar vector?

Thanks

Robert

2. Oct 28, 2008